Dementia rates increase rapidly with age, affecting over 40% of people above 90. To understand how to prevent it, we must look at both brain needs and damaging factors. The brain, though only 2% of body weight, uses over 20% of the body’s energy, requiring fuel, oxygen, and constant stimulation. Without regular use, like muscles, the brain can atrophy.

Damage accelerates with genetics, but epigenetics — how genes are expressed — plays a large role. Lifestyle choices can either activate or suppress genes. Another major factor is inflammation, especially chronic low-grade inflammation, driven by oxidative stress, toxins, food allergies, and poor gut health.

One of the top contributors to dementia is excess alcohol. While moderate drinking may offer some benefits, frequent overconsumption harms the brain, liver, gut, and promotes inflammation and insulin resistance.

Another is refined carbohydrates, particularly added sugars and processed starches. Sugar leads to blood sugar spikes and fatty liver — both strongly linked to cognitive decline. Fructose, especially from sugary drinks or dried fruits, behaves like alcohol in the liver. Even “natural sugars” in juices act like added sugar due to lack of fiber.

Starches, especially from refined grains, break down quickly into glucose and raise blood sugar faster than table sugar. This causes frequent insulin spikes, and over time, insulin resistance. Recent findings show that the brain does rely on insulin to absorb glucose. So, when brain cells become insulin resistant, they can’t get enough fuel — even when blood sugar is high.

This leads to a paradox: more sugar leads to a starving brain, often called “type 3 diabetes.” The brain becomes energy-deprived while the body has an overload of sugar. This isn’t due to poor design, but rather a modern lifestyle overloaded with processed carbs and sugar — something our ancestors never faced.

Top 10 Foods That Harm the Brain and Contribute to Dementia

Sugar – The primary cause of insulin resistance, which blocks glucose from entering the brain. Excess sugar also prevents ketone production, fuels fatty liver, is highly addictive, and contributes to gut imbalance and leaky gut.

Fish (High in Mercury) – While wild-caught fish like sardines and cod provide essential Omega-3s, predatory fish such as tuna and swordfish accumulate mercury, a neurotoxin. Farmed fish can also be harmful due to low-quality feed and chemical exposure.

Dirty Dozen (Heavily Sprayed Produce) – Certain fruits and vegetables like strawberries, apples, spinach, and peppers are often grown with high levels of pesticides, which can harm the brain and body, especially in people with weak detox systems.

Artificial Sweeteners – Aspartame and sucralose (Splenda) are neurotoxic, damage gut bacteria, and may cause DNA damage. They’re used to replace sugar but can increase cravings and disrupt metabolism. Natural options like Stevia and Monk Fruit are safer in moderation.

Bad Fats – Trans fats and industrial seed oils (misnamed “vegetable oils”) are oxidized and inflammatory due to harsh processing. Excess Omega-6 from these oils contributes to chronic inflammation. Fried foods worsen the damage.

Lectins and Gluten – Found in nightshades (e.g., tomatoes, eggplants), grains, and especially modern wheat, lectins and gluten can damage the gut lining, leading to leaky gut and brain inflammation, especially in sensitive individuals.

Excess Caffeine – In small doses, caffeine helps with focus. In large amounts, it stresses the body, raises cortisol, and disrupts melatonin, which is essential for sleep and brain recovery.

Food Additives – Artificial colors, flavors, preservatives, and texturizers make food look appealing but are often toxic and unrecognizable to the body. If mold won’t eat it, should we?

Farmed Fish (Low-Quality) – Poorly raised farmed fish may be loaded with hormones, antibiotics, and pollutants. Only sustainably and cleanly farmed fish may be safe.

Pesticides and Modern Farming – Our genes have never adapted to modern chemicals used in the last 50 years. The cumulative effect of these toxins burdens the body and can lead to cognitive decline.